Pointless Kirby Trivia #13
In Kirby's Dream Land, if you pause the game (+, if you're playing using NSO) and wait for a bit, Kirby starts dancing on the pause screen.

Pointless Kirby Trivia #14
In a similar fashion, In Kirby Tilt and Tumble, if you you tilt in any direction on the pause screen, another, smaller Kirby will poke out from 'off screen' to look at the 'main' Kirby, from whichever direction you tilt towards. [Screenshot from Failboat's Tilt and Tumble stream]

Pointless Kirby Trivia #1
In Forgotten Land, while tipped over in Locker Mouth mode, if you try to move, Kirby's eyes are closed as he's wriggling, except with the last one in Alivel Mall. With that one his eyes are open.

Pointless Kirby Trivia #2
In Kirby Star Allies; the water texture(??) on the water blobs around Mareen Moon isn't seamless. You can see where the water starts and ends.

Pointless Kirby Trivia #3
Also in Kirby Star Allies, Planet Earthfall seems to have gotten cut in half at some point? All other planets in Far-flung Starlight Heroes are globes, Earthfall however is only half a globe.
Maybe Falluna Moon is part of the missing half?

Pointless Kirby Trivia #4
In Kirby and the Forgotten Land, if you follow the peaceful, walking Awoofy in Alivel Mall all the way to the end of the room, you can see them walking through a banner and 'into' the wall.
If you follow them, you'll notice there's actually a well hidden hole in the wall and you get Star Coin from going in there.

Pointless Kirby Trivia #5
Here's the Point of Arrival's normally foggy forest area without fog (achieved thanks to the Hammer Jump glitch)

Pointless Kirby Trivia #6
Planet Frostak's ring is a bunch of (vaguely star-shaped) snowflakes.

Pointless Kirby Trivia #7
Some of the engravings on Jambandra Base depict what seems to be a snowflake, flame and lightning bolt, representing The Three Mage Sisters and their respective elements.

Pointless Kirby Trivia #8
Enemies Kirby swallows do not die, they simply reappear elsewhere.
Source: Polygon interview with Shinya Kumazaki and Tatsuya Kamiyama

Pointless Kirby Trivia #9
In Kirby and the Forgotten Land, in the Stage Clear screens, the eye sparkles and colours in Elfilin's eyes keep moving even though everything else is still.

Pointless Kirby Trivia #10
In Forgotten Land, if you go out of bounds with the hammer jump glitch, standing on certain pieces of geometry puts Kirby in a falling state.
After being in this state for a while, he poofs and reappears, similarly to as if he'd fallen off a cliff or something. He just doesn't take damage in this case.
Video link [Warning for slight texture strobe]

Pointless Kirby Trivia #11
In Forgotten Land, when Meta Knight's about to throw a bunch of sword beams at you, Galaxia glows yellow, but if you've stolen Galaxia and he has his original sword from Adventure, the sword glows purple.

Pointless Kirby Trivia #12
Kirby can run up more or less 90 degree angle walls in some places in Forgotten Land.

I loved Kumazaki just POPPING OFF during the Dedede's themes medley lmao. What a man. Everyone else looked like they were about lose it.
(For those who don't know, Shinya Kumazaki, the current director of the Kirby series, voices Dedede in the games)
I also love how he was like 'Look at these cool people!' during the ending.

The Kirby series could not have gotten a better director.

Kirby's VA's outfit was really cute. ;w; Fitting, I guess.
Also, loved the Super Clash credits song and the Welcome To The New World performances! I was NOT expecting to see who's clearly the stand-in(?) for Neichel, the person than in-canon sang that song in the game. I wonder if they kept their face hidden on purpose...?

So we have Fecto Forgo, Fecto Elfilis, Soul Forgo, Chaos Elfilis and the multiple bosses called Forgo [Insert character name here].
There's no Forgo Elfilis, just Elfilis and Forgo being combined with other words.
Fecto seems to most likely be derived either from 'infect' or 'perfect/complete'.

So, what if Forgo and Elfilis are separate beings?
There's quite a few people assuming Elfilis is one of the 4 Heroes of Yore that originally sealed away Void Termina due to their and Forgo Leon's + Phantom Clawroline's attacks resembling some of Void Termina's attacks as well as the sky, especially during the Chaos Elfilis fight, somewhat resembles Void. While I'm not personally completely on board with this theory due to a variety of reasons that're best spared for another post, for a moment let's assume they are.
If Elfilis really was one of the heroes that sealed away the Destroyer of Worlds, why would they then go and wreck house on some random planet? As the Lab Discovera elevator ride states: "From the moment ID-F86 arrived on our planet, it began a campaign of destruction that threatened the native wildlife of our entire world".
To add, why would it only go for the wildlife? There's nothing that states it was trying to harm the people on the planet (which can be safely assumed to have been the ancients). It's also worth noting that while more subtlely under Fecto Forgo's control, Leon is able to speak just fine, but when Fecto Forgo took full control of him, his speech became more primitive, in lack of better words.
If Elfilis and Forgo are two separate beings in the same body, could it be that Forgo is a parasite of some kind?
It would explain why a supposed hero would suddenly turn mad, why it mostly seems to be after wildlife, why it's speech capability seems to be on a lower level as well as conviniently explaining the possible 'infect' part of Fecto Elfilis etc.

I also have another explanation for Elfilis behaviour, still assuming they were one of the four heroes.
They could have gotten corrupted/possessed by Void/the Jamba heart in some way. Void is capable of possession and the Jamba heart has been proven to be capable of corrupting people.
Yeah, that's about all I've got for now.
It's late and I'll be adding more stuff here if/when I come up with/find out something.

Some brief Kirby theory rambles I posted on my Fanexus some time back.
Spoilers for KatFL and some others!

1. Currently thinking about how final bosses related to the ancients all seem to have wings and horns (Galacta Knight, Magolor Soul, Void Termina, Elfilis, with the one exception being Star Dream, which technically still at least had wings in phase 1).

2.And also about how the main colour palette for the phantom bosses in Forgotten Land is pretty similar to Aeon Hero Dark (Magenta, dark purple, green/cyan).
The green -> cyan is admittedly a stretch, but no one can stop me from making the connection.

3.Found out about this on Tumblr, and fact-checked it myself; Apparently Morpho Knight's sword turn into Galaxia briefly during the attacks where the sword glows..